If you've got a fridge full of half eaten jars of questionable freshness, toss them all away—what are you, cheap? Once you're done with that, grab some Digital Day Counters and attach them to all your new food, letting the counter keep track of how many days that sour cream has been sitting there, waiting to be eaten.

The counters affix themselves via suction or magnetism, depending on your jar type, and cost only $12 each. You could achieve the same functionality with some masking tape and a Sharpie pen, but where's the gadgetry in that? – Jason Chen